1. Field of the Invention
The present invention relates to a detecting device which detects whether solution is being supplied to a tank, and to a processing device which utilizes the detecting device.
2. Description of the Related Art
In processing tanks in an automatic developing apparatus such as a developing tank and a fixing tank, as photosensitive materials are subjected to processing, the processing solutions in the tanks deteriorate due to processing and deteriorate over time. To compensate therefor, replenishing solutions must be replenished in order to activate the processing solutions in the tanks. Further, the amount of processing solution within the processing tank decreases due to evaporation and due to the processing solution being carried out from the tank on the photosensitive material. In these cases as well, replenishing solution is replenished so as to prevent the surface level of the processing solution within the processing tank from falling.
Usually, a flow path is formed by piping extending from a reserve tank, in which replenishing solution is stored, to the processing tank. The replenishing solution is discharged to above the processing tank by the driving of a pump.
In such an automatic developing apparatus, if the amount of the replenishing solution with the reserve tank is not monitored, there may not be any replenishing solution when replenishing is necessary, which may lead to problems with the operation of the automatic developing apparatus. The following methods are known as methods of monitoring the existence of the replenishing solution in the reserve tank.
A method in which a sealed reserve tank is used is known, and the existence of the replenishing solution is detected on the basis of the load applied to the pump which discharges the replenishing solution from the tank.
However, this method cannot use an open-type reserve tank.
A method in which the surface level of the solution in the tank is monitored by a level sensor mounted at the tank is used, so that the existence of the replenishing solution is detected.
In this method, it can be determined whether or not there is replenishing solution in the tank, but it cannot be determined whether replenishing solution is actually being supplied to the processing tank.
A method is known in which a rotary blade or the like, which rotates due to the flow of the replenishing solution, is provided in the piping for supplying the replenishing solution. By monitoring the rotational state of the rotary blade, the existence of the replenishing solution is detected.
In this method, if a state in which replenishing solution is not replenished continues over a long period of time, problems in operation may arise due to solidification of chemical agents contained in the replenishing solution.